This invention relates to electronic or electric sequential blasting systems and more particularly to such systems for use in mining operations. The invention relates in particular to connectors for use in systems of the aforementioned kind including wired networks for electronic and electric detonators, hereinafter referred to as electrically operable detonators.
Wired networks for electrically operable detonators include a blast box and insulated electricity conductive leading wires extending from the blast box, the leading wires being connected by connecting means to the blast box. Detonators, each including an insulated conductive umbilical cord, are connected via the cords to the leading wire, by means of connecting means. Insulated conductive extension wires or extension pieces may be provided between the detonators or between sections of the leading wire. These extension wires are also connected to the leading wire by connecting means.
In one known system, the connections are made by in situ removing protective sheathes at bare ends of the umbilical cords of the detonators and twisting the bare ends about bare regions in the leading wire, to make ohmic or galvanic contact. This method of connecting the detonators to the leading wire is laborious, time consuming and the system as such may not be safe and reliable enough.
In another known system, inductive coupling is utilised. A C-shaped magnetic core with a plurality of windings of the detonator umbilical cord wound thereon, is clipped onto the leading wire.
In yet another system a custom made so-called insulation displacement connector (IDC) is used. An IDC includes prongs or teeth capable of piercing the insulation of an embedded conductor to which it is to be connected, to make electrical contact with the conductor. These connectors are cumbersome to use, especially in multi-conductor connections where time and skill are required to ensure that each tooth penetrates to the selected conductor with which contact is required. Furthermore, these connectors are difficult to instal, because they have a preferred orientation relative to the wire to which they are to be connected for best results.